Piano tuning-pin.



P. SACK sz-F. AQTYLER.

PIANO TUNING PIN.

APPLICATION FILED SEPT. 15,1908.

Patented Nov. 30, 1909.

MWW,

UNITED sTATEs FRANK SACK AND FRANK A. TYLER, OF ST. MARY, NEBRASKA.

PIANO TUNING-PIN.

Specification of Letters Patent.

Application filed September 15, 1908.

Patented Nov. 30, 1909.

Serial No. 453,108.

T o all whom it may concern.'

Be it known that we, FRANK Sack and FRANK A. TYLER, residing at St. Mary, in the county of Johnson and State of N ebraska, have invented a new and Improved Piano Tuning-Pin, of which the following is a specification.

`A,Orr invention has for its object to provide an improved tuning pin for pianos, of a simple anddurable construction, and adapted for being conveniently applied for use and held locked from turning or working loose, and the said invention comprehends, generally, an improved form of tuning pin, having its penetrating end split longitudinally and means operable from the outer or string receiving end for expanding the split end and holding the separated portions expanded, the said separated or split end members having their outer surfaces formed so as to tightly bite into the wooden wrest plank or base into which the pins are driven.

In its more complete nature, our invention embodies a tubular piano tuning pin having a string receiving head portion formed with a key engaging boss, a main threaded shank portion and a supplemental shank or penetrating end of less diameter than the main threaded shank portion, said end being split longitudinally and having longitudinal external grooves and a coacting means adjustably mounted Within the tubular pin and operable from the outer end of the pin for expanding the slitted penetrating end and holding the same locked to the expanded position and to cause the said penetrating end to bite into the wood for preventing the pin from turning and working loose.

In its still more subordinate features this invention consists in certain details of construction hereinafter fully described, specifically pointed out in the appended claims and illustrated in the accompanying drawing, in which:-

Figure 1 is a vertical section of our improved construction of tuning pin, the same being shown as driven into place, and the split end in normal shape. Fig. 2, is a similar view, and showing the locking and expanding means adjusted to expand the split ends to bite into the wood base. Fig. 3, is a perspective view that illustrates the pin in position on the wrest plank and the string attached. Fig. l, is a perspective view of the two parts that constitute the complete pin separated, and Fig. 5, is an enlarged detail i longitudinal section of the expanding end of the pin. Fig. 6 is a cross section on the line 6 6 of Fig. 5. Fig. 7 is a detail section showing another method of slitting the end of the pin. y

Our pin is more especially adapted for use on the usual types of wooden wrest plank members to which the pins are usually attached. The wrest planks are indicated by the reference letter A in the drawings, and the plank A is reinforced as usual by the metal plate B. The metal plate B has the customary openings o to receive the wooden key receiving plugs as shown in Fig. l. It should be understood, however, that the arrangement of the wooden wrest plank member may be in any well known or approved manner, one end of the wrest plank A having the usual hitch pin g for holding one end of the string.

The main shank portion 2 is of the usual length and of uniform diameter, except that portion below the string receiving space and the threaded portion. The body is so threaded that after the pin has been driven in and the tuning key applied, the said threads will screw into the wood and draw the pin positively into its bearing. The pin is also formed with a supplemental shank member 23 which is all of that part that extends from the threaded part, and the said shank member 23 is of a slightly reduced diameter so that after being driven home the lower end of the pin as it enters or is driven into the wood makes a socket of slightly less diameter than the threaded body or portion of the pin and thereby leaves suflicient surface on the walls of the socket in the wood for the threaded part of the pin to securely bite into as the pin is forced home during the final turning during tuning.

Our tuning pin C consists of a tubular body having the usual key receiving head l, a main shank portion 2, the upper end of which terminates with an annular rim or shoulder 3 that forms the base for the key head l and which has an aperture 30 for receiving the end` A() of the string A, the said shank portion having its upper end smooth as at 20, that forms the winding or string drawing part of the pin.

The lower or supplemental shank member has its end made tapering or is of slightly conical shape to facilitate the driving thereof and the said end is slotted longitudinally l at one or more places as at 24:, as clearly shown in Figs. 1 and 2, by reference to which it will also be noticed that the bore ai of the pin terminates some distance inside the penetrating end of the pin and at the end it is tapering or cone-shaped as at the reason for which will presently appear. *The outer surface of the supplemental shank portion is grooved longitudinally to form teeth or serrations 25.

`D designates the locking and expanding means that forms a component part of our complete pin structure and the same comprises a long pin (l, one end of which is tapering or cone shaped as at d for engaging with the conical shaped portion m of thesplit shank portion, the outerI end having a screw neckd2 and a screw head cl3, the neck Z2 being provided to engage the internally threaded portion 2G of the bore m of the-pin in the manner clearly shown in Figs. l and 2.

F rom the foregoing taken in connection with the drawing the complete arrangement of our pin and the advantages thereof will be readily apparent.

In applying the pin to the wrest plank A in the first instance, the same is driven in the usual manner, the shank end being in the usual position.

The string having been brought to the desired pitch, the screw pin D is then forced inwardly which causes the end of the said pin D to engage the conical sur' ace zu and thereby cause the split end of the pin C to expand and bite into the wood, and since the grooves in the split end run lengthwise of the pin, the bite of the split end holds the pin from turning and the threads on the pin keep it from working outwardly, thereby insuring a perfect locking of the pin to its tuned position.

Vhen the string needs another tuning, the tuner first loosens the lock screw D to allow the split end of the pin to contract, to permit the vpin to turn freely when applying the key. After the pin has been further turned to bring the string up to the desired tone, the lock or screw pin D is again tightened to expand the split end of the pin as before.

Having thus described our invention what we claim and desire to secure by Letters Patent, is

l. A tubular tuning pin for pianos, comprising a head and a main shank for receiving the string together with a supplemental or penetrating end, said end being longitudinally slotted to provide expansible portions, means for expanding said expansi- A ble portions, and means at the head of the pin for operating said expanding means.

2. A tubular tuning pin for pianos, having a key receiving head, having an annular collar with a string lreceiving aperture, a main shank portion that receives the string, a supplemental or penetrating shank portion, Vthe latter being longitudinally slotted and an expander `within the pin bore for engaging with the expanding or slotted end of the pin, said expander project-ing through the head of the pin.

S. A .tuning pin for pianos, comprising a tubular member having a head and a string receiving or main shank portion, and a supplemental shank portion, the latter being of less diameter than the main shank portion and being longitudinally slotted to form expansible members, and a means adjustable within the pin for expanding the slotted end ofthe pin.

4. A tubular piano tuning lpin having` a head portion formed with a collar having an aperture, a main shank portion femuing the string, said shank portion being externally screw threaded, a supplemental shank portion at the end of the threaded portion of less diameter than the threaded portion, said supplemental shank portion being slitted at the end, the bore of the supplemental shank portion being of less diameter than that of the main shank portion and a screw plunger' operable in the bore, having its penetrating end formed to engage the bore portion in the slitted end of the pin.

5. As a newarticle, a piano tuning pin comprising a tubular member having a key receiving head portion, the bore ofsaid portion being threaded, a main shank on-which the string is wound, said main shank having an externally threaded surface, a main shank or penetrating end, of less diameter than the main shank, said penetrating end being longitudinally slitted, the bore in said supplemental shank stopping short of the outer end and having` a conical termination, combined with a screw plunger pin having a threaded neck to engage the threaded portion of the bore, a conical end for engaging the conical termination of the bore, and a screw head, the slotted or penetrating end of the pin having longitudinally extended grooves as set forth.

G. As a new article of manufacture, a piano tuning pin comprising a tubular member having a key-receiving head portion, a main shank on which the string is wound, said main shank terminating in a slitted end to form expansible members, and means at the head of the pin and projecting through the pin to engage the expansible members to actuate the same.

7. A piano tuning pin comprising a hollow tubular member formed with a key receiving head portion at one end, and slitted at the other to form expansible members and an expander within the pin to engage said slitted end to actuate the same.

S. A piano tuning pin comprising a hollow tubular member formed with a key reat the other to form expansible members, an

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members, and means Within the pin for eX- panding said resilient members.

FRANK SACK. FRANK A. TYLER.

Witnesses:

H. Soi-IUMANN, H. C. SCHUMANN. 

